I keep getting a missing right or left parenthesis error when I try to create my tables with a foreign key, but when I remove the foreign key my code has no problem creating the tables. I need the code to run with the foreign keys.
--deletes respective tables previously created
drop table DEPARTMENT;
drop table POSITION;
drop table EMPLOYEE;
drop table COMPANY;
drop table DEGREE;
drop table GRAD_INFO;
drop table STUDENT;
CREATE TABLE Department
(
Dept_Name varchar(255) PRIMARY KEY, --primary key
Dept_Phone_Num numeric(35) not null
);
CREATE TABLE Position
(
Position_Name varchar(255) NOT NULL PRIMARY KEY, --primary key
Position_Salary decimal(10, 2) not null,
Employee_num numeric(35) not null,
CONSTRAINT fk_Dept_Name
FOREIGN KEY Dept_Name REFERENCES Department (Dept_Name) --foreign key
);
CREATE TABLE Employee
(
EmployeeID INT NOT NULL PRIMARY KEY, --primary key
Employee_Salary DECIMAL(10,2) DEFAULT NULL,
Employee_FName VARCHAR(30) DEFAULT NULL,
Employee_LName VARCHAR(30) NOT NULL,
Employee_Address VARCHAR(30) DEFAULT NULL,
Employee_Phone_Num INT(10) DEFAULT NULL,
Employee_Email VARCHAR(30) NOT NULL,
Employee_Status VARCHAR(10) NOT NULL,
CONSTRAINT Position_Name
FOREIGN KEY Position_Name REFERENCES Position(Position_Name), --foreign key
CONSTRAINT fk_Dept_Name
FOREIGN KEY Dept_Name REFERENCES Department(Dept_Name) --foreign key
);
CREATE TABLE Company
(
Comp_Name VARCHAR(20) NOT NULL PRIMARY KEY, --primary key
Position_Offer VARCHAR(30) NOT NULL,
Salary_Offer DECIMAL(10,2) NOT NULL,
Signing_Bonus DECIMAL(10,2) DEFAULT NULL,
Comp_Phone_Num INT(10) NOT NULL,
Comp_Address VARCHAR(30) NOT NULL,
CONSTRAINT fk_Employee_ID
FOREIGN KEY Employee_ID REFERENCES Employee (Employee_ID), --foreign key
CONSTRAINT fk_Dept_Name
FOREIGN KEY Dept_Name REFERENCES Department (Dept_Name) --foreign key
);
CREATE TABLE Degree
(
Degree_Type varchar(255) PRIMARY KEY, --primary key
Academic_Status varchar(255) not null,
Academic_Level varchar(255) not null,
Major varchar(255) not null,
Minor varchar(255) default null
);
CREATE TABLE Gead_Info
(
Grad_Status VARCHAR(255) NOT NULL PRIMARY KEY, --primary key
College_Name VARCHAR(255) NOT NULL,
Num_Of_Degrees NUMERIC(10) NOT NULL,
Grad_Date NUMERIC(6) NOT NULL,
CONSTRAINT fk_Degree_Type
FOREIGN KEY Degree_Type REFERENCES Degree(Degree_Type) --foreign key
);
CREATE TABLE Student
(
Student_ID NUMERIC(10) NOT NULL PRIMARY KEY, --primary key
Student_FName VARCHAR(20) NOT NULL,
Student_LName VARCHAR(20) NOT NULL,
Student_Address VARCHAR(20) NOT NULL,
Student_Email VARCHAR(20) NOT NULL,
Student_Phone_Num VARCHAR(10) NOT NULL,
CONSTRAINT fk_Comp_Name
FOREIGN KEY Comp_Name REFERENCES Company(Comp_Name), --foreign key
CONSTRAINT fk_Grad_Status
FOREIGN KEY Grad_Status REFERENCES Gead_Info(Grad_Status) --foreign key
);
The degree table is the only table where I don't get an error.
Should I use an alter table instead after I create all the tables or is there another way to solve my problem?
edit: updated code
I think your most immediate issue is with the Department table not having a comma between the two CONSTRAINT clauses. You might also run into issues with your Position table's CONSTRAINT clause referencing the Position table instead of the Employee table, although honestly I don't think you need that relationship defined at all since the Employee table already has a foreign key constraint with Position. And like what was stated earlier, your table definitions aren't in the right order so you have some tables referencing other tables before those others are created.
Give this a shot to see if the syntax works. I've added the column definition for the foreign key in Position, put parentheses around the foreign key column name in the CONSTRAINT clause, and removed the space between Department and the left paren in the CONSTRAINT clause. If this script works, make the same changes to your other table defs.
CREATE TABLE Department(
Dept_Name varchar(255) Primary Key, --primary key
Dept_Phone_Num numeric(35) not null
);
CREATE TABLE Position(
Position_Name varchar(255) not null Primary Key, --primary key
Position_Salary decimal(10, 2) not null,
Employee_num numeric(35) not null,
Dept_Name varchar(255) not null,
CONSTRAINT fk_Dept_Name FOREIGN KEY (Dept_Name) REFERENCES Department(Dept_Name) --foreign key
);
Related
CREATE TABLE student
(
student_id INT PRIMARY KEY,
first_name VARCHAR(40) NOT NULL,
last_name VARCHAR(40) NOT NULL,
birth_day DATE NOT NULL,
sex VARCHAR(1) NOT NULL,
student_email_address VARCHAR(40) NOT NULL UNIQUE,
student_password VARCHAR(10) NOT NULL UNIQUE,
student_nick_name VARCHAR(10) NOT NULL,
student_qualification VARCHAR(10) NOT NULL,
student_documents VARCHAR(255) NOT NULL,
student_image VARCHAR(100) NOT NULL
);
CREATE TABLE student_feedback
(
sr_no BIGSERIAL PRIMARY KEY,
student_id INT NOT NULL,
feedback_type VARCHAR(10) NOT NULL,
feedback_text VARCHAR(200) NOT NULL,
FOREIGN KEY (student_id) REFERENCES student(student_id)
);
CREATE TABLE online_exam
(
exam_id INT PRIMARY KEY,
exam_title VARCHAR(20) UNIQUE NOT NULL,
exam_duration_min INT NOT NULL,
total_questions INT NOT NULL,
marks_per_right_answer INT NOT NULL,
marks_per_wrong_answer INT NOT NULL,
passing_marks INT NOT NULL,
exam_status VARCHAR(2)
);
CREATE TABLE exam_subjects
(
sub_id INT,
exam_id INT,
sub_name VARCHAR(20) NOT NULL,
sub_desc VARCHAR(20) NOT NULL,
UNIQUE(sub_id,exam_id),
PRIMARY KEY(sub_id,exam_id),
FOREIGN KEY (exam_id) REFERENCES online_exam(exam_id) ON DELETE CASCADE
);
CREATE TABLE sub_questions
(
sub_id1 INT,
ques_id INT,
ques_text VARCHAR(150) NOT NULL,
ques_attachments VARCHAR(255),
option_1 VARCHAR(20) NOT NULL,
option_2 VARCHAR(20) NOT NULL,
option_3 VARCHAR(20) NOT NULL,
option_4 VARCHAR(20) NOT NULL,
UNIQUE(sub_id1,ques_id),
PRIMARY KEY (sub_id1,ques_id),
FOREIGN KEY (sub_id1) REFERENCES exam_subjects(sub_id) ON DELETE CASCADE
);
CREATE TABLE ques_answers
(
ans_id INT,
ques_id INT,
ans VARCHAR(20) NOT NULL,
PRIMARY KEY (ans_id,ques_id),
FOREIGN KEY (ques_id) REFERENCES sub_questions(ques_id) ON DELETE CASCADE
);
CREATE TABLE exam_registration
(
student_id INT,
exam_id INT,
exam_date_time TIMESTAMP NOT NULL,
PRIMARY KEY (student_id,exam_id),
FOREIGN KEY (student_id) REFERENCES student(student_id) ON DELETE CASCADE,
FOREIGN KEY (exam_id) REFERENCES online_exam(exam_id) ON DELETE CASCADE
);
CREATE TABLE exam_result
(
student_id INT,
exam_id INT,
sub_id INT,
marks_scored INT NOT NULL,
correct_ques INT NOT NULL,
wrong_ques INT NOT NULL,
grade VARCHAR(10) NOT NULL,
PRIMARY KEY(student_id,exam_id,sub_id),
FOREIGN KEY (student_id) REFERENCES student(student_id) ON DELETE CASCADE,
FOREIGN KEY (exam_id) REFERENCES online_exam(exam_id) ON DELETE CASCADE,
FOREIGN KEY (sub_id) REFERENCES exam_subjects(sub_id) ON DELETE CASCADE
);
Output :
CREATE TABLE,
CREATE TABLE,
CREATE TABLE,
CREATE TABLE,
There is no unique constraint matching given keys for referenced table "exam_subjects", relation "sub_questions" do not exist,
CREATE TABLE,
There is no unique constraint matching given keys for referenced table "exam_subjects".
Why am I getting "there is no unique..." error in postgresql? How to solve it? Please help.
In your table exam_subjects the primary key is a compossed key (PRIMARY KEY(sub_id, exam_id))
Therefore, your table sub_questions must have both columns to create the constraint, otherwise you get the error about unique constraints (or you can create a unique field acting as primary key, and create a unique index on both columns sub_id and exam_id)
New to SQL, can't figure out what is wrong in my given code. all it says is:
Incorrect syntax near 'DESCRIBE'. [41,1]
I have tried taking off the semi-colons. I really just don't know what it wants from me.
Here is my code. Anything helps, thank you!
-- Write the query to create the 4 tables below.
CREATE TABLE client (
id INT NOT NULL IDENTITY(1,1),
first_name VARCHAR(255) NOT NULL,
last_name VARCHAR(255) NOT NULL,
dob DATE NOT NULL,
PRIMARY KEY (id),
CONSTRAINT (full_name) UNIQUE (first_name, last_name)
);
CREATE TABLE employee (
id INT NOT NULL IDENTITY(1,1),
first_name VARCHAR(255) NOT NULL,
last_name VARCHAR(255) NOT NULL,
dob DATE NOT NULL,
date_joined DATE NOT NULL,
CONSTRAINT (full_name) UNIQUE (first_name, last_name),
PRIMARY KEY (id)
);
CREATE TABLE project (
id INT NOT NULL IDENTITY(1,1),
cid INT NOT NULL,
name VARCHAR(255) NOT NULL,
notes TEXT,
UNIQUE (name),
FOREIGN KEY (cid) REFERENCES client(id)
);
CREATE TABLE works_on (
eid INT NOT NULL,
pid INT NOT NULL,
start_date DATE NOT NULL,
PRIMARY KEY (eid, pid),
FOREIGN KEY (eid) REFERENCES employee(id),
FOREIGN KEY (pid) REFERENCES project(id)
);
-- Leave the queries below untouched. These are to test your submission correctly.
-- Test that the tables were created
DESCRIBE client;
DESCRIBE employee;
DESCRIBE project;
DESCRIBE works_on;
-- Test that the correct foreign keys were created
SELECT TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME,REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE REFERENCED_TABLE_SCHEMA = 'grade';
For MariaDB (and MySQL) the correct syntax for IDENTITY(1,1), is AUTO_INCREMENT, and CONSTRAINT names are not enclosed in (). Any column that is defined as AUTO_INCREMENT must also be declared as a PRIMARY KEY (this is only an issue with the project table). So your CREATE TABLE commands should look like this:
CREATE TABLE client (
id INT NOT NULL AUTO_INCREMENT,
first_name VARCHAR(255) NOT NULL,
last_name VARCHAR(255) NOT NULL,
dob DATE NOT NULL,
PRIMARY KEY (id),
CONSTRAINT full_name UNIQUE (first_name, last_name)
);
CREATE TABLE employee (
id INT NOT NULL AUTO_INCREMENT,
first_name VARCHAR(255) NOT NULL,
last_name VARCHAR(255) NOT NULL,
dob DATE NOT NULL,
date_joined DATE NOT NULL,
CONSTRAINT full_name UNIQUE (first_name, last_name),
PRIMARY KEY (id)
);
CREATE TABLE project (
id INT NOT NULL AUTO_INCREMENT,
cid INT NOT NULL,
name VARCHAR(255) NOT NULL,
notes TEXT,
PRIMARY KEY (id),
UNIQUE (name),
FOREIGN KEY (cid) REFERENCES client(id)
);
CREATE TABLE works_on (
eid INT NOT NULL,
pid INT NOT NULL,
start_date DATE NOT NULL,
PRIMARY KEY (eid, pid),
FOREIGN KEY (eid) REFERENCES employee(id),
FOREIGN KEY (pid) REFERENCES project(id)
);
Demo on dbfiddle
Attached is my attempt at creating a database for the following entity relationship diagram. But I keep getting the following error:
"SQL0538N FOREIGN KEY "ADVISOR_STUDENT" does not conform to the
description of the parent key of table or nickname "KISHANPA.STUDENT".
SQLSTATE=42830"
for these 4 tables: advisor, prereq, teaches, takes. The rest of the tables seem to work fine. It would be greatly appreciated if someone can guide me int eh right direction. Thanks
ER Diagram
Schema Diagram
create table department (
dept_name varchar(30) not null,
building varchar(30),
budget numeric(7,2),
constraint department_key primary key (dept_name)
);
create table instructor (
iid char(9) not null,
name varchar(30) not null,
dept_name varchar(30) not null,
salary numeric(6,2),
constraint instructor_key primary key (iid, dept_name),
constraint instructor_dept foreign key(dept_name)
references department on delete no action
);
create table student (
sid char(9) not null,
name varchar(30) not null,
tot_cred smallint,
dept_name varchar(30) not null,
constraint student_key primary key (sid, dept_name),
constraint student_dept foreign key(dept_name)
references department on delete no action
);
create table course (
course_id char(8) not null,
title varchar(30) not null,
dept_name varchar(30) not null,
credits int not null,
constraint course_key primary key (course_id, dept_name),
constraint course_dept foreign key(dept_name)
references department on delete no action
);
create table advisor (
sid char(9) not null,
iid char(9) not null,
constraint advisor_key primary key (sid, iid),
constraint advisor_student foreign key(sid)
references student on delete no action,
constraint advisor_instructor foreign key (iid)
references instructor on delete no action
);
create table prereq (
course_id char(8) not null,
prereq_id char(8),
constraint prereq_key primary key (course_id),
constraint prereq_course foreign key(course_id)
references course on delete no action,
constraint prereq_precourse foreign key(prereq_id)
references course on delete no action
);
create table classroom (
building varchar(30) not null,
room_number varchar(10) not null,
capicity integer,
constraint classroom_key primary key (building, room_number)
);
create table time_slot (
time_slot_id varchar(10) not null,
day varchar(10) not null,
start_time time not null,
end_time time,
constraint time_slot_key primary key (time_slot_id, day, start_time)
);
create table section (
course_id char(8) not null,
sec_id varchar(10) not null,
semester char(1) not null,
year numeric (4,0) not null,
building varchar(30) not null,
room_number varchar(10) not null,
time_slot_id varchar(10) not null,
constraint section_key primary key(course_id, sec_id, year,
building, room_number, time_slot_id),
constraint section_classroom foreign key(building, room_number)
references classroom on delete no action
);
create table teaches (
iid char(9) not null,
course_id char(8) not null,
sec_id varchar(10) not null,
semester char(1) not null,
year numeric(4,0) not null,
constraint teaches_key primary key (iid, course_id, sec_id,
semester, year),
constraint section_instrictor foreign key(iid)
references instructor on delete no action,
constraint teaches_section foreign key(course_id, sec_id, semester, year)
references section on delete no action
);
create table takes (
sid char(9) not null,
course_id char(8) not null,
sec_id varchar(10) not null,
semester char(1) not null,
year numeric(4,0) not null,
grade real,
constraint takes_key primary key (sid, course_id, sec_id,
semester, year),
constraint student_takes foreign key(sid)
references student on delete cascade,
constraint takes_section foreign key(course_id, sec_id,
semester, year) references section on delete cascade
);
Your problem is on your key for student. You must have the same column to join tabes whith FK. Modify you table student like this :
create table student (sid char(9) not null, name varchar(30) not null, tot_cred smallint, dept_name varchar(30) not null, constraint student_key primary key (sid), constraint student_dept foreign key(dept_name) references department on delete no action);
The docs say this:
A foreign key references a primary key or a unique key in the same or
another table. A foreign key assignment indicates that referential
integrity is to be maintained according to the specified referential
constraints.
Your "advisor_student" references "sid", but that is not the primary key. You would need to include the department or change the design.
Your primary keys don't match your schema diagram for several tables.
Instructor, student, and course all have dept_name in the primary key in your DDL, but according to the Schema diagram, and logically as well, this field should not be a part of the primary key for any of those tables. In addition, the primary key of section does not match the Schema diagram. It should be (course_id, sec_id, semester, year) You have a lot of extra fields in there. That will cause problems with the foreign key constraints on teaches and takes.
Finally, the time_slot file both in the schema, and in the DDL have what I would call a questionable, given no other input, primary key. Should just be time_slot_id to my mind, then you can build a foreign key from section to time_slot as well.
I'm having problems with creating tables:
CREATE TABLE EMPLOYEE
(
employee_id NUMBER(5) NOT NULL UNIQUE,
position VARCHAR2(100) NOT NULL,
name VARCHAR2(255) NOT NULL,
salary NUMBER(6) NOT NULL
CONSTRAINT employee_pk PRIMARY KEY (employee_id)
);
CREATE TABLE PROJECT
(
project_id NUMBER(5) NOT NULL UNIQUE,
name VARCHAR(100) NOT NULL,
budget NUMBER(6) NOT NULL,
consultant_leader NUMBER(5) NOT NULL,
developer_leader NUMBER(5) NOT NULL,
project_leader NUMBER(5) NOT NULL,
CONSTRAINT project_pk PRIMARY KEY (PROJECT_ID),
CONSTRAINT fk_leader
FOREIGN KEY (consultant_leader, developer_leader, project_leader)
REFERENCES EMPLOYEE (employee_id, employee_id, employee_id)
);
In the last section, when I try to reference the employee's table employee_id, I'm getting ORA-00957. I think it's because the 3 different leader type foreign key references the same employee_id, but as far as I know, it should not be a problem. Is the syntax wrong?
Your immediate problem is that you need three foreign key relationships, not one with three columns.
But, there is no need to declare a primary key as being unique. So, I would recommend:
CREATE TABLE EMPLOYEE (
employee_id NUMBER(5) NOT NULL PRIMARY KEY,
position VARCHAR2(100) NOT NULL,
name VARCHAR2(255) NOT NULL,
salary NUMBER(6) NOT NULL
);
CREATE TABLE PROJECT (
project_id NUMBER(5) NOT NULL PRIMARY KEY,
name VARCHAR(100) NOT NULL,
budget NUMBER(6) NOT NULL,
consultant_leader NUMBER(5) NOT NULL,
developer_leader NUMBER(5) NOT NULL,
project_leader NUMBER(5) NOT NULL,
CONSTRAINT fk_leader FOREIGN KEY (consultant_leader)
REFERENCES EMPLOYEE (employee_id),
CONSTRAINT fk_leader FOREIGN KEY (developer_leader)
REFERENCES EMPLOYEE (employee_id),
CONSTRAINT fk_leader FOREIGN KEY (project_leader)
REFERENCES EMPLOYEE (employee_id)
);
You don't need to put the PRIMARY KEY constraint in-line, of course. The advantage of declaring it separately is that you can give the constraint a name to your liking.
I think you should create three distinct FK: FK_Consultant, FK_developer, FK_projleader
the Staff table references the branch table
CREATE TABLE Staff(
StaffNo VARCHAR(5) NOT NULL,
firstName VARCHAR(15) NOT NULL UNIQUE,
lastName VARCHAR(15) NOT NULL,
position VARCHAR(10) NOT NULL,
salary INTEGER
DEFAULT 3000,
CHECK (salary BETWEEN 3000 AND 25000),
email VARCHAR(25),
branchNo CHAR(6) NOT NULL,
PRIMARY KEY (StaffNo),
FOREIGN KEY (branchNo) REFERENCES Branch (branchNo));
and at the same time the branch table references the Staff table
create table Branch(
branchNo char(6) not null primary key,
street varchar(30) not null,
city varchar(20),
postCode char(5) not null,
ManagerNo varchar(5) not null,
foreign key (ManagerNo) references Staff(StaffNo));
Since your tables reference each other in the Foreign Keys you will get an error on either table creation if the other table has not been created yet. I would suggest that you remove the creation of the FOREIGN KEYs to separate ALTER TABLE statements:
CREATE TABLE Staff(
StaffNo VARCHAR(5) NOT NULL,
firstName VARCHAR(15) NOT NULL UNIQUE,
lastName VARCHAR(15) NOT NULL,
position VARCHAR(10) NOT NULL,
salary INTEGER
DEFAULT 3000,
CHECK (salary BETWEEN 3000 AND 25000),
email VARCHAR(25),
branchNo CHAR(6) NOT NULL,
PRIMARY KEY (StaffNo)
);
create table Branch(
branchNo char(6) not null primary key,
street varchar(30) not null,
city varchar(20),
postCode char(5) not null,
ManagerNo varchar(5) not null
);
alter table staff
add constraint fk1_branchNo foreign key (branchNo) references Branch (branchNo);
alter table branch
add constraint fk1_ManagerNo foreign key (ManagerNo) references Staff (StaffNo);
See SQL Fiddle with Demo
You can remove one reference from one table and keep the other.then you can retrieve data using the remainig reference.Is there any problem with that?